Thyroxine Supplementation in Small for Gestational Age (SGA) Infants With Birth Weight <1500g and TSH 6-20 mIU/ml

NCT07625722 | Not Yet Recruiting

• 1 other identifier: SWYX：NO.2025-1019-1
• Study Type: interventional
• Target: 106
• Locations: 1 country
• Sites: 1

Brief Summary

The primary objective of this clinical trail is to evaluate whether early supplementation of levothyroxine (L-T4) at a dosage of 8 ug/kg/d, initiated in the second week of life, improves physical growth and neurodevelopmental outcomes at 2 years of corrected age in Small for Gestational Age (SGA) infants with birth weights \< 1500g and TSH levels between 6 and 20 mIU/ml. Preterm infants in the intervention group will receive 8 ug/kg/d of L-T4, while the control group will receive no supplementation. Physical growth will be assessed through height, weight, and head circumference, while neurodevelopmental status will be evaluated using the Bayley-IV scales and cranial MRI imaging findings.

Conditions

Preterm; SGA and Growth; Thyroid Function; Neurodevelopment Outcome

Outcome Measures

Primary Outcomes (8)

• Cognitive function evaluated by Bayley-IV

  At 24 months corrected age

• Motor function evaluated by Bayley-IV

  At 24 months corrected age

• Language function evaluated by Bayley-IV

  At 24 months corrected age

• Social-Emotional evaluated by Bayley-IV

  At 24 months corrected age

• Adaptive behavior evaluated by Bayley-IV

  At 24 months corrected age

• Body length（cm）assessed by the WHO 0-5 years Child Growth Standards.

  At 24 months corrected age

• Head circumference（cm）assessed by the WHO 0-5 years Child Growth Standards.

  At 24 months corrected age

• Weight（kg）assessed by the WHO 0-5 years Child Growth Standards.

  At 24 months corrected age

Secondary Outcomes (2)

• the incidence of neonatal morbidities （EUGR、PNAC、MBDP、Moderate to severe BPD、Stage III or higher ROP）during the initial hospitalization

  at 36 weeks of postmenstrual age

• All-cause Mortality

  At 24 months corrected age

Study Arms (2)

control group

NO INTERVENTION

intervention group

EXPERIMENTAL

Drug: Levothyroxine Sodium (LT4) Tablets

Interventions

Levothyroxine Sodium (LT4) Tablets DRUG

The intervention group will receive oral levothyroxine (L-T4) initiated on postnatal day 14 at a starting dose of 8 ug/kg/day. Thyroid function will be monitored every 2-4 weeks until 36 weeks postmenstrual age or hospital discharge, with subsequent follow-up at corrected ages of 40 weeks, 3, 6, 12, 18, and 24 months. The L-T4 dosage will be dynamically titrated to achieve therapeutic targets of TSH \< 5 mIU/L and FT3/FT4 levels within the upper 50% of the age-specific reference range. Treatment will be discontinued if therapeutic targets are sustained at a dosage below 2 ug/kg/day or if FT3/FT4 levels exceed the upper limit of normal.

intervention group

Eligibility Criteria

• Age: 2 Weeks - 2 Weeks
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Preterm infants born Small for Gestational Age (SGA) with a birth weight \< 1500g；
• Admitted to a participating Neonatal Intensive Care Unit (NICU) within 7 days of birth；
• Serum concentrations of TSH, FT4, and FT3 are measured weekly during the first and second weeks of life，any single TSH measurement during this period is between 6 and 20 mIU/mL；
• Written informed consent obtained from the parents.

You may not qualify if:

• Diagnosis of Congenital Hypothyroidism (CH) with serum TSH \> 20 mIU/mL within the first 2 weeks of life and receiving L-T4 treatment;
• Persistent serum TSH \< 6 mIU/mL throughout the first 2 weeks;
• Elevated thyroid hormone levels(T3, T4, FT3, or FT4) above the reference range within the first 2 weeks;
• Diagnosis of Grade III or IV Intraventricular Hemorrhage (IVH) within the first 2 weeks of life;
• Presence of major congenital malformations of vital organs or known chromosomal/genetic disorders;
• History of maternal thyroid disease or maternal use of thyroid-related medications.

Sponsors & Collaborators

• Shandong Provincial Hospital: lead

Study Sites (1)

Shandong Provincial Hospital Affiliated to Shandong First Medical University

Jinan, Shandong, 250021, China

Location

MeSH Terms

Conditions

Premature Birth

Interventions

Thyroxine; Tablets

Condition Hierarchy (Ancestors)

Obstetric Labor, Premature; Obstetric Labor Complications; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases

Intervention Hierarchy (Ancestors)

Thyroid Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Amino Acids, Aromatic; Amino Acids, Cyclic; Amino Acids; Amino Acids, Peptides, and Proteins; Dosage Forms; Pharmaceutical Preparations

Central Study Contacts

Yonghui Yu

CONTACT

+8615168887236; alice20402@126.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chief physician

Study Record Dates

• First Submitted: May 13, 2026
• First Posted: June 4, 2026
• Study Start (Estimated): June 20, 2026
• Primary Completion (Estimated): June 20, 2027
• Study Completion (Estimated): June 20, 2029
• Last Updated: June 4, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)